agg/include/agg_rendering_buffer_dynarow.h

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2021-12-27 20:14:31 +01:00
//----------------------------------------------------------------------------
// Anti-Grain Geometry - Version 2.4
// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
//
// Permission to copy, use, modify, sell and distribute this software
// is granted provided this copyright notice appears in all copies.
// This software is provided "as is" without express or implied
// warranty, and with no claim as to its suitability for any purpose.
//
//----------------------------------------------------------------------------
// Contact: mcseem@antigrain.com
// mcseemagg@yahoo.com
// http://www.antigrain.com
//----------------------------------------------------------------------------
//
// class rendering_buffer_dynarow
//
//----------------------------------------------------------------------------
#ifndef AGG_RENDERING_BUFFER_DYNAROW_INCLUDED
#define AGG_RENDERING_BUFFER_DYNAROW_INCLUDED
#include <cstring>
#include "agg_array.h"
namespace agg
{
//===============================================rendering_buffer_dynarow
// Rendering buffer class with dynamic allocation of the rows.
// The rows are allocated as needed when requesting for span_ptr().
// The class automatically calculates min_x and max_x for each row.
// Generally it's more efficient to use this class as a temporary buffer
// for rendering a few lines and then to blend it with another buffer.
//
class rendering_buffer_dynarow
{
public:
typedef row_info<int8u> row_data;
//-------------------------------------------------------------------
~rendering_buffer_dynarow()
{
init(0,0,0);
}
//-------------------------------------------------------------------
rendering_buffer_dynarow() :
m_rows(),
m_width(0),
m_height(0),
m_byte_width(0)
{
}
// Allocate and clear the buffer
//--------------------------------------------------------------------
rendering_buffer_dynarow(unsigned width, unsigned height,
unsigned byte_width) :
m_rows(height),
m_width(width),
m_height(height),
m_byte_width(byte_width)
{
std::memset(&m_rows[0], 0, sizeof(row_data) * height);
}
// Allocate and clear the buffer
//--------------------------------------------------------------------
void init(unsigned width, unsigned height, unsigned byte_width)
{
unsigned i;
for(i = 0; i < m_height; ++i)
{
pod_allocator<int8u>::deallocate((int8u*)m_rows[i].ptr, m_byte_width);
}
if(width && height)
{
m_width = width;
m_height = height;
m_byte_width = byte_width;
m_rows.resize(height);
std::memset(&m_rows[0], 0, sizeof(row_data) * height);
}
}
//--------------------------------------------------------------------
unsigned width() const { return m_width; }
unsigned height() const { return m_height; }
unsigned byte_width() const { return m_byte_width; }
// The main function used for rendering. Returns pointer to the
// pre-allocated span. Memory for the row is allocated as needed.
//--------------------------------------------------------------------
int8u* row_ptr(int x, int y, unsigned len)
{
row_data* r = &m_rows[y];
int x2 = x + len - 1;
if(r->ptr)
{
if(x < r->x1) { r->x1 = x; }
if(x2 > r->x2) { r->x2 = x2; }
}
else
{
int8u* p = pod_allocator<int8u>::allocate(m_byte_width);
r->ptr = p;
r->x1 = x;
r->x2 = x2;
std::memset(p, 0, m_byte_width);
}
return (int8u*)r->ptr;
}
//--------------------------------------------------------------------
const int8u* row_ptr(int y) const { return m_rows[y].ptr; }
int8u* row_ptr(int y) { return row_ptr(0, y, m_width); }
row_data row (int y) const { return m_rows[y]; }
private:
//--------------------------------------------------------------------
// Prohibit copying
rendering_buffer_dynarow(const rendering_buffer_dynarow&);
const rendering_buffer_dynarow& operator = (const rendering_buffer_dynarow&);
private:
//--------------------------------------------------------------------
pod_array<row_data> m_rows; // Pointers to each row of the buffer
unsigned m_width; // Width in pixels
unsigned m_height; // Height in pixels
unsigned m_byte_width; // Width in bytes
};
}
#endif